Watch: Support Path Pattern Matching

[davidgfitzgerald]

Request

It would be nice if the watch path attribute behaved like the ignore attribute. For example, path could accept wildcards such as *.

At the very least it would help to have some more detail in the API documentation adding that (at least for the time being) pattern matching does not work on path.

Reference: https://docs.docker.com/reference/compose-file/develop/

Example

I would like the convenience of being able to do this:

services:
 frontend:
 build:
 context: ./frontend
 dockerfile: Dockerfile
 ports:
 - "5173:5173"
 develop:
 watch:
 - action: rebuild
 path: frontend/*.json
 - action: rebuild
 path: frontend/*.js

instead of the verbose (yet explicit):

services:
 frontend:
 build:
 context: ./frontend
 dockerfile: Dockerfile
 ports:
 - "5173:5173"
 develop:
 watch:
 - action: rebuild
 path: frontend/jsconfig.json
 - action: rebuild
 path: frontend/package-lock.json
 - action: rebuild
 path: frontend/package.json
 - action: rebuild
 path: frontend/eslint.config.js
 - action: rebuild
 path: frontend/svelte.config.js
 - action: rebuild
 path: frontend/tailwind.config.js
 - action: rebuild
 path: frontend/vite.config.js

Nice To Have

Bonus points for allowing multiple path entries in a single rebuild action:

services:
 frontend:
 build:
 context: ./frontend
 dockerfile: Dockerfile
 ports:
 - "5173:5173"
 develop:
 watch:
 - action: rebuild
 path: frontend/*.json frontend/*.js

Currently, passing a space separated list is silently interpreted as a single path. So, the below example (misleadingly) does not match frontend/package.json nor frontend/vite.config.js

 - action: rebuild
 path: frontend/package.json frontend/vite.config.js

[jhrotko]

I would propose to introduce a new keyword paths for rebuild and restart actions, since the path has a 1 to 1 relation to target for sync++ actions.
Under this assumption, the new keyword paths you could also have the pattern matching safely as it would support multiple files (as the pattern matching might resolve to more than one file). As for path, we should be careful for the pattern matching; perhaps returning an error explaining the matched files if it resolves to multiple files.

Or we can change path to be either a string or a list in the json schema and during validation make sure the above assumptions. However, I think usability becomes more complicated as there are different conditions for different actions

[davidgfitzgerald]

@jhrotko paths sounds reasonable, at the slight expense of the user having to understand that both path and paths exist. Which is not obscene by any stretch of the imagination, just slightly more mental overhead for the user.

I guess it's a tradeoff between making the API as smooth as possible for the user and an implementation that actually achieves the desired behaviour. I am guess that extending the behaviour of path has complications on the implementation I am unaware of.

[jhrotko]

I created a POC in these branches (feature-wild-star-watch-path):

• compose
• compose-go

in these branches the implementation is under the path which can now receive a string or a list of strings and also validates the * pattern matching.

If you want to try, clone my fork/branch and run make build.

in your compose.yml you can write something along the lines

...
develop:
 watch:
 - path: SOME/PATH/*.txt
 action: rebuild
 - path: 
 - FILE1
 - FILE2
 action: restart

you can run with the specific compose build (from the make build) by running

PATH/TO/JHROTKO/FORK/compose/bin/build/docker-compose up --watch

[ndeloof]

On #12584 I proposed to keep using a single path as base to monitor filesystem for changes, and introduce a dedicated include attribute so one can declare patterns to restrict which actual file changes should be considered by action:

 develop:
 watch:
 - action: rebuild
 path: frontend
 include:
 - *.json
 - *.js